Pf 18607600 | Mathematics homework help

A tensile test specimen starts with a length of 2.000 inches between the gage marks. After the test, the length is 2.138 inches. What is the elongation of the material?

A steel bar, which measures 5.000 inches at 20 degrees F, is heated to 1050 degrees F in a brazing operation. The length of the bar at the high-temperature point is..

If a 0.250-inch square bar is pulled in tension by a force of 1250 pounds. The tensile stress produced in the part is ______psi. A. 0.0002 B. 480 C. 2000 D. 20,000

PF  18607600

One physical test that can reveal a material’s ability to withstand high shock loads at low temperatures is a A. Charpy impact test. B. Young’s tensile test. C. Vickers hardness test. D. Brinell bend test. 2. Manufacturing materials can be divided into the classifications of A. solids, liquids, gases, and ions. B. ferrous, nonferrous, elements, and compounds. C. metals, nonmetals, metalloids, and gases. D. metals, ceramics, polymers, and composites. 3. Cold-working metals in manufacturing operations A. makes grains larger, thus making them more ductile. B. requires quenching and tempering to do additional procedures. C. produces round, spherical grains. D. breaks large grains into smaller ones, thus hardening and strengthening the metals. If a steel part has become hardened through rolling operations and requires additional machining and forming operations, A. it should be quenched and tempered before the additional manufacturing steps. B. later steps will require sharper cutting tools because of the increased hardness of the part. C. normalizing or annealing may be in order to make manufacturing operations easier and faster. D. the age-hardening process should be delayed until the part is completely finished. If a steel part has become hardened through rolling operations and requires additional machining and forming operations, 6. Two allotropes of iron are A. iron carbide and chromium. B. body-centered cubic and hexagonal close-packed. C. ferrite and austenite. D. cementite and bauxite

8. Materials with large grains A. always have isotropic yield-strength characteristics. B. are more ductile and malleable than small-grained materials. C. can be achieved only through the addition of special alloying elements that ensure large grain structures. D. have very low levels of impurities. 9. The slope of a material’s stress-versus-strain curve is A. determined by the amount of force applied to the material specimen. B. a measure of the stiffness of the material. C. about 29 106 psi. D. an indication of how strong a material is. 14. A 1-inch square bar that’s 10 inches long is weighed and found to be 3.21 pounds. This bar is most likely made from A. aluminum. B. steel. 15. The material AISI 4130 is A. an aluminum alloy. B. not a currently valid material designation. C. a type of manganese. D. a chromium-molybdenum steel alloy. 16. Composite materials can be reinforced C. copper. D. gold. A. with fibers, particles, and dispersion-hardening particulates. B. for strength, but never in more than one direction. C. with steel where light weight and low manufacturing costs are called for. D. with polymers to achieve the highest strength levels. 17. Tensile stress in a circular material such as a rod or bolt can be calculated by A. dividing the applied force by the diameter of the rod. B. multiplying the diameter of the rod by the applied force. C. dividing the area of the rod by the applied force. D. dividing the applied force by the area of the rod. 18. Phase changes in a metal A. occur because of manufacturing forming operations. B. happen only as the metal changes from a liquid to a solid, or vice versa. C. occur with temperature changes when the crystal structure changes. D. can’t be achieved with non-pure, real word metals. 19. Composite materials are A. not suitable for applications that require isotropic properties. B. formed from a bulk material matrix and a reinforcement material embedded within the matrix. C. all limited as to the maximum operating temperature because low-melting-point materials are often included within the structure. D. easy to produce and use in manufacturing operations. 20. Rockwell hardness is a popular method of measuring hardness in a material because it A. is the method available that’s useful for testing steel materials. B. corresponds to the actual value of a material’s tensile strength. C. is the only scale that covers the wider range of hardnesses found in nonmetalic materials. D. requires no special skills, and is fast and accurate 9. A. determined by the amount of force applied to the material specimen. B. a measure of the stiffness of the material. C. about 29 106 psi. D. an indication of how strong a material is. 10. Heat-treating procedures for metals A. involve variations of temperature and rates of heating and cooling to achieve desired properties. B. can be applied to only nonferrous materials. C. are almost always are done after finishing a manufactured part. D. are necessary prior to machining or forging metal parts. 11. Technical ceramics A. are all highly magnetic. B. are abrasives used in advanced machining applications. C. are mostly limited to building material applications. D. can be both electrical insulators and conductors. 12. Hardness testing in manufacturing operations A. is not very reliable and needed only for special applications. B. can quickly reveal that a material has been processed correctly. C. can verify actual strength levels of materials used. D. requires specially constructed specimens for destructive testing